A standard transcontainer for shipping produce, frozen food, or the like is basically an elongated parallepipedal box having a closed front end wall, a rear wall formed by a pair of doors, side walls, a roof or top wall, and a floor. Most of the walls are formed as two metal sheets or skins sandwiching a mass of closed-cell insulation. The top skin of the floor is provided with a plurality of longitudinally extending T-section rails that define longitudinal passages or slots and the side walls have vertical grooves. The front wall is provided with a refrigerating apparatus that draws air in from upper regions of the container, chills it, and expels it to front ends of the floor passages so that it is distributed through the container to cool all the freight inside the container.
Such a transcontainer meeting the international ISO standards has an electrically driven refrigerating apparatus that is set right into the front end wall. Air is sucked in adjacent the roof, chilled, and then fed back under the load. In the taller 9 ft 6 in so-called high-cube containers the cool air is also fed in along the side walls. Getting such a container, which can be 40 ft to 45 ft long, fully cooled is very difficult and the cargo in the rear door area frequently is insufficiently chilled. Since the load temperature is normally determined by a sensor located at the chiller's intake, such a system often is running with the rearmost parts of the load some 5.degree. to 10.degree. warmer than desired but, due to inefficient air circulation, is seemingly running correctly. The result is insufficiently frozen goods, often rising to +2.degree. C. to +12.degree. C.
The main problem with the known containers is that they are made as large as possible. The refrigerating plants are appropriately dimensioned, but once the containers are fully loaded, air circulation is so poor that some of the cargo is insufficiently cooled. The rear door region is particularly problematic because it is so far from the cooling plant. This plant itself must be dimensioned small enough to fit in the front wall with 300 mm to 400 mm wide passages on each side for air movement. The air distribution is ultimately quite uneven, with the core of the load being adequately cooled and rear and side parts of the load thawing.